The regulations in force that regulate that assembly of electric control boards establish a minimum distance of 30 mm. between the consecutive pushbuttons or indicators of a specific format and which are horizontally lined up in a battery.
On the other hand, the front surface of the component, above all in the case of pushbuttons, must be as large as possible to allow localization and operation thereof.
Now, then, generally pushbuttons and similar components are manufactured with a cylindric shape, although the base of the seat may be circular or even quadrangular. In both cases, it is conventional that the frame of the pushbutton is obtained in a single body in which the base is formed, be the base circular or quadrangular, and besides the side casing of the pushbutton itself, thus different pieces and molds are used in each model.
Such a circumstance makes the manufacturing of the unit more expensive and increases the amount and variety of pieces which are all negative factors.
In order to reduce these costs and to eliminate the above cited inconveniences and problems, there are presently solutions which consist of coupling between the body of the pushbutton and the ring that surrounds it an auxiliary piece whose outer contour is square. This solution, although it permits the converting of a circular based pushbutton into a square based one, still has the inconvenience that in order to place the square base in place, it is necessary to dismount the ring that surrounds the pushbutton. The ring axially retains the square base, which results in an increase of assembly costs. Thus, given the scarce dimensional margin that remains between two consecutive pushbuttons, some open sides have been established. These open sides are taken advantage of by inserting some auxiliary pieces that connect the bases, but this makes it necessary to assemble some terminal covers at the ends of each set of pushbuttons. This implies even more assembly, and thus, this solution is not the most satisfactory and desirable one.
Besides, conventionally there are basically two sizes of pushbuttons and similar components that make up both manufacturing series, thus, each one of these series offers some specific services and uses.
However, on many occasions, where the required features are complied with by these two series, for any reason it may be convenient to exchange or combine the components of both series.
Now then, in said cases or circumstances, the holes already made in control panels could be enlarged, but never reduced, thus it is not feasible to substitute a component of a larger series by one of the smaller series.
Consequently, there is no unification with regard to the diameter of the holes made in these control panels corresponding to electric installations or the like, not allowing the indistinct assembly of components of one format or another, in terms of the particular case and needs of the installation.